A novel data processing method to improve the interference metric precision of laser beams based on improved genetic algorithms (GAs) is presented. The improved GAs to fit curves is compared with the conventional GAs and the conventional least square method to fit curves. Using the improved genetic algorithms, the results show that the influence on the precision of measurement from errors in quantitating the size of image element of CCD and on the image-gathering cards in CCD optic interference measurement is removed, and that the multi-extremum of object function is resolved. The location precision of interference stripes is also increased, and the intensity distribution of the stripes is fitted accurately. The error of curve fitting is also discussed . GAs is shown to be very well in possession of robustness and adaptability.